Previously, hydrophilic pressure sensitive adhesives based on PEO polymer networks have been prepared. Examples of hydrophilic pressure sensitive adhesives based on PEO polymer networks are disclosed in U.S. Pat. No. 4,684,558 (Keusch et al.); U.S. Pat. No. 4,706,680 (Keusch et al.); and U.S. Pat. No. 4,777,954 (Keusch et al.) which teach the preparation of an adhesive poly(ethylene oxide) hydrogel sheet by subjecting an aqueous PEO solution to high energy radiation.
Also, European Patent Publication 0 271 292 (Ansell) teaches the preparation of a skin friendly PSA by reacting a polyfunctional isocyanate with a polyoxyalkylene diol monoalkyl ether and a hydroxyl-containing ester of (meth)acrylic acid and then crosslinking the polymer (optionally in the presence of 40 to 65% water) by means of irradiation.
Also, U.S. Pat. No. 4,855,077 (Shikinami et al.) and the Derwent Abstract of Japanese Patent Publication 62-139628 (Takiron), teach the preparation of an ion-conductive polymer adhesive agent by reacting an alkylene oxide containing polyol with a polyurethane polyisocyanate prepolymer in the presence of an ionic compound which can include water.
U.S. Pat. No. 4,497,914 and 4,650,817 (both Allen et al.) also teach the reaction of a polyoxyalkylene polyol with an organic polyisocyanate while incorporating a hydrophilic filler to give an elastomeric adhesive for skin contacting applications. The presence of water is specifically excluded, presumably to prevent undesirable side reaction with the isocyanate.
U.S. Pat. No. 4,273,135 (Larimore et al.) discloses poly(oxyethylene) (also known as PEO) as one of the non-ionic synthetic hydrophilic polymers useful as a conductive material for a biomedical electrode and suggests plasticization with alcohols as a means of imparting conformability.
Methods of preparing difunctional (telechelic) poly(ethylene glycol)s with free-radically polymerizable end groups are known in the art. For example, U.S. Pat. No. 3,928,299 (Rosenkranz et al.) and U.S. Pat. No. 5,4,233,425 (Tefertiller et al.) both disclose products resulting from reaction of poly(alkyleneoxide)s with compounds such as isocyanatoethyl methacrylate. U.S. Pat. No. 3,509,234 (Burlant et al.) discloses a reaction of a hydroxylated polymer with first a diisocyanate and then a hydroxyalkyl (meth)acrylate. Also, U.S. Pat. Nos. 4,777,276; 4,837,290; 4,914,223; and 4,996,243 (all Rasmussen et al.) disclose reaction products obtained from vinyl dimethyl azlactone and poly(ethylene glycol) diamines.